Problem: Express your answer as a mixed number simplified to lowest terms. $18\dfrac{4}{6}-13\dfrac{9}{15} = {?}$
Explanation: Separate the whole numbers from the fractional parts: $= {18} + {\dfrac{4}{6}} - {13} - {\dfrac{9}{15}}$ Bring the whole numbers together and the fractions together: $= {18} - {13} + {\dfrac{4}{6}} - {\dfrac{9}{15}}$ Subtract the whole numbers: $=5 + {\dfrac{4}{6}} - {\dfrac{9}{15}}$ Simplify each fraction: $= 5 + {\dfrac{2}{3}} - {\dfrac{3}{5}}$ Find a common denominator for the fractions: $= 5+\dfrac{10}{15}-\dfrac{9}{15}$ Subtract the fractions: $= 5+\dfrac{1}{15}$ Combine the whole and fractional parts into a mixed number: $= 5\dfrac{1}{15}$